Update python generator for registerering event handlers.

Author: lizlooney

src/blocks/mrc_event_handler.ts

@@ -29,6 +29,7 @@ import { createFieldFlydown } from '../fields/field_flydown';
 import { createFieldNonEditableText } from '../fields/FieldNonEditableText';
 import { MRC_STYLE_EVENT_HANDLER } from '../themes/styles';
 import * as toolboxItems from '../toolbox/items';
+import * as storageModule from '../storage/module';
 import * as storageModuleContent from '../storage/module_content';
 
 export const BLOCK_NAME = 'mrc_event_handler';
@@ -359,11 +360,37 @@ export function pythonFromBlock(
   code = generator.scrub_(block, code);
 
   generator.addClassMethodDefinition(funcName, code);
-  generator.addEventHandler(sender, eventName, funcName);
+  generateRegisterEventHandler(block, generator, sender, eventName, funcName);
 
   return '';
 }
 
+function generateRegisterEventHandler(
+    block: EventHandlerBlock,
+    generator: ExtendedPythonGenerator,
+    sender: string,
+    eventName: string,
+    funcName: string) {
+  // Create the line of code that will register this event handler.
+  let fullSender = '';
+  if (block.mrcSenderType === SenderType.ROBOT) {
+    fullSender = 'self.' + sender;
+  } else if (block.mrcSenderType === SenderType.MECHANISM) {
+    switch (generator.getModuleType()) {
+      case storageModule.MODULE_TYPE_ROBOT:
+        fullSender = 'self.' + sender;
+        break;
+      case storageModule.MODULE_TYPE_OPMODE:
+        fullSender = 'self.robot.' + sender;
+        break;
+    }
+  }
+  if (fullSender) {
+    generator.addRegisterEventHandlerStatement(
+        fullSender + '.register_event_handler("' + eventName + '", self.' + funcName + ')\n');
+  }
+}
+
 // Functions used for creating blocks for the toolbox.
 
 export function addRobotEventHandlerBlocks(

src/editor/extended_python_generator.ts

@@ -79,8 +79,7 @@ export class ExtendedPythonGenerator extends PythonGenerator {
   private hasAnyEventHandlers = false;
 
   private classMethods: {[key: string]: string} = Object.create(null);
-  // For eventHandlers, the keys are the function name.
-  private eventHandlers: {[key: string]: {sender: string, eventName: string}} = Object.create(null);
+  private registerEventHandlerStatements: string[] = [];
   // Opmode details
   private details : OpModeDetails | null  = null;
 
@@ -180,11 +179,8 @@ export class ExtendedPythonGenerator extends PythonGenerator {
     this.classMethods[methodName] = code;
   }
 
-  addEventHandler(sender: string, eventName: string, funcName: string): void {
-    this.eventHandlers[funcName] = {
-      'sender': sender,
-      'eventName': eventName
-    }
+  addRegisterEventHandlerStatement(registerEventHandlerStatement: string): void {
+    this.registerEventHandlerStatements.push(registerEventHandlerStatement);
   }
 
   getComponentPortParameters(): string[] {
@@ -214,12 +210,10 @@ export class ExtendedPythonGenerator extends PythonGenerator {
       const classDef = 'class ' + className + '(' + simpleBaseClassName + '):\n';
       const classMethods = [];
 
-      if (this.eventHandlers && Object.keys(this.eventHandlers).length > 0) {
+      if (this.registerEventHandlerStatements && this.registerEventHandlerStatements.length > 0) {
         let code = 'def register_event_handlers(self):\n';
-        for (const funcName in this.eventHandlers) {
-          const event = this.eventHandlers[funcName];
-          code += this.INDENT + 'self.' + event.sender + '.register_event_handler("' +
-              event.eventName + '", self.' + funcName + ')\n';
+        for (const registerEventHandlerStatement of this.registerEventHandlerStatements) {
+          code += this.INDENT + registerEventHandlerStatement;
         }
         classMethods.push(code);
       }
@@ -233,8 +227,8 @@ export class ExtendedPythonGenerator extends PythonGenerator {
         }
         classMethods.push(this.classMethods[name])
       }
-      this.eventHandlers = Object.create(null);
       this.classMethods = Object.create(null);
+      this.registerEventHandlerStatements = [];
       this.componentPorts = Object.create(null);
       code = classDef + this.prefixLines(classMethods.join('\n\n'), this.INDENT);
       if (decorations){